Stormwater treatment ponds are common, but there are few tools to evaluate their performance. Traditional techniques, i.e. dye traces, take significant amounts of time and are impractical. Computational fluid dynamics is increasingly being used to design and evaluate ponds, but often neglects the effects of vegetation. This study looks at the CFD modelling of a stormwater pond in Lyby, Southern Sweden, both with and without vegetation. The Residence Time Distribution is an established means of evaluating treatment capability of a pond. CFD modelling of solute transport is carried out to obtain RTDs, which are then compared to experimental RTDs obtained from the pond. The capability and benefits of including vegetation in CFD modelling of ponds are examined.